[[Category:OPS235]][[Category:OPS235 Labs]]{{Admon/caution|THIS IS AN OLD VERSION OF THE LAB|'''This is an archived version. Do not use this in your OPS235 course.'''}}= Using Virtual Machines Logical Volume Management and Software Package Management=

Virtualization:* Learn how to add and remove software packages on your different Linux systems.:* [http://docs.fedoraprojectLearn how to properly adjust your various Linux file systems by using and managing LVM both graphically (fedora2) as well as command line (fedora3).org/virtualization-guide/f12/en-US/html/ Fedora 12 Virtualization Guide]

A ''virtual machine'' is a software simulation of a computer which can be used as though it were actual hardware==Linux Command Online Reference==Each Link below displays online manpages for each command (via [http://linuxmanpages. It's possible to run multiple virtual machines on one computer, reducing hardware requirements and introducing flexibilitycom/ http://linuxmanpages. Some common uses of virtualization includecom]):

{|width="100%" cellpadding="5"|'''LVM Information Utilities:'''|'''LVM Management Utilities:'''|'''Additional Utilities:'''|- valign="top"|*[http://linuxmanpages.com/man8/vgs.8.php vgs]*[http://linuxmanpages.com/man8/lvs.8.php lvs]*[http://linuxmanpages.com/man8/pvs.8.php pvs]* Software testing -- Using multiple operating systems simultaneously on a single computer for testing and experimentation[http://linuxmanpages.com/man8/vgdisplay.8.php vgdisplay]* Network simulation -- Testing network services, protocols, and security scenarios with a small number of computers[http://linuxmanpages.com/man8/lvdisplay.8.php lvdisplay]* Isolation -- Protecting multiple sets of data by storing them on multiple virtual machines[http://linuxmanpages.com/man8/pvdisplay.8.php pvdisplay]|* Server consolidation [http://www.centos.org/docs/5/html/Deployment_Guide-en-US/s1-system-config- Reducing the number of physical servers in a network by moving physical machines to virtual machineslvm. This saves hardware, administration, cooling, and electricity costs, and it can increase the utilization of hardware html system-config-lvm] (by ensuring that the hardware is not under-loadedTutorial)*[http://linuxmanpages.com/man8/lvextend.8.php lvextend]*[http://linuxmanpages.com/man8/resize2fs.8.php resize2fs]*[http://linuxmanpages.com/man8/lvcreate.8.php lvcreate]*[http://linuxmanpages.com/man8/lvreduce.8.php lvreduce]*[http://linuxmanpages.com/man8/pvcreate.8.php pvcreate]* Load-balancing and disaster recovery -- It is possible to migrate virtual machines between different physical machines, to ensure that a workload is balanced across multiple computers, to allow routine hardware maintenance and upgrading, and to compensate for hardware failure or other disasters[http://linuxmanpages.com/man8/vgextend.8.php vgextend]|*[http://linuxmanpages.com/man8/mount.8.php mount]*[http://linuxmanpages.com/man8/umount.8.php umount]*[http://linuxmanpages.com/man8/yum.8.php yum]*[http://linuxmanpages.com/man8/rpm.8.php rpm]|}

In ==Resources on the web==Additional links to tutorials and HOWTOs:'''Please read this lab, you will create three virtual machines. This also gives you page to get an opportunity overview of LVM:'''<br /><br />:* [[Logical Volume Management]] ('''Note:''' It is recommended to return to experiment with different ways of installing Fedora. Later in this course you will install another operating system distribution in guide as a virtual machinesreference when performing the next several investigations):* [http://fedoranews.org/alex/tutorial/rpm/ Using the RPM Utility]:* [http://www.centos.org/docs/5/html/yum/ Using the YUM Utility]

* Installation sourceRPM maintains a database of installed software. This information is very useful to system administrators. In Lab 3, you queried that database using RPM with the -q argument. When you query the RPM database, you can separately specify::** CD Which packages you want to do an <u>operational task</u> (like installing or DVD** Hard disk** USB flash driveremoving a package), using a '''select-option''':** Network HTTP or NFS software repositoryWhat <u>information</u> you want about those packages, using a '''query-option'''

When you installed Fedora in [[OPS235 Lab 2|Lab 2]], you did it interactively -- you manually specified all of '''Perform the installation options, and then the installation process was started. This is fairly convenient for single-machine installations, but is time-consuming and possibly error-prone when repeated for dozens, hundreds, or thousands of machines. following steps:'''

For large installations# Using information from the man page for <code>rpm</code>, it's possible to specify the installation options fill in a file so that no user intervention is required. This is called a ''kickstart'' installation.this information:

{|width="100%" border= Instructions ="1" cellpadding="5"|-!Option!Meaning!Select or query option?!Example command|-| -a|Select all packages|select-option| |-| -l| | | |-| -i|Show the package information.| | |-| -f filename| | | |-|packagename|Select just this package|select-option| |}

{{Admon/tip|Update your Fedora Installation|It's a good idea to ensure that your Fedora installation is fully updated before proceeding. You can update your system == Investigation 2: How do you install and remove software with the graphical tool located on the menu at >System>Administration>Software Update (or type the command <code>gpk-update-view</code>), or by typing either of these commands: <code>pkcon update</code> or <code>yum update</code>}}RPM? ==

# Install Use the Fedora virtualization software: <code>yum groupinstall "Virtualization"</code> graphical file manager (Nautilus) to change to the directory on your Installation DVD. Go to the sub-directory called '''Packages''' and then go to the sub- note that directory '''l''' (for files beginning with the letter l like the virtualization software is in three parts:## A system service named ''libvirtd'lynx''' that manages the VMspackage).## Tools to manage virtualization, including the You should see a file called: <code>virtlynx-2.8.7-manager8.fc17.x86_64.rpm</code> graphical tool and # Execute the following command: <code>virshrpm -i lynx-2.8.7-8.fc17.x86_64.rpm</code> # Issue an RPM query to check that lynx is installed. Record this commandin your lab log-line tool.## The actual virtual machines themselvesbook.# Start Issue the virtualization servicefollowing command: <code>service libvirtd startrpm -e lynx</code># Start Issue an RPM query to verify that lynx is no longer installed. Record this command in your lab log-book.# Move to the graphical tool by selecting appropriate sub-directory for packages that begin with the menu option Applications>System Tools>Virtual Machine Manager or by typing letter '''b'''.# Issue the following command : <code>virtrpm -i BackupPC-3.2.1-manager7.fc17.x86_64.rpm</code>and note the result

=== Installing from the Network =Investigation 3: How do you install and remove software with ''yum''? ==

=== Installing {{Admon/note|Internet Connection|In order for yum to work you require a connection to the Internet. Establish this connection by using Kickstart ===the browser to log into SeneNET}}

# Change to your home directory. <ol> <li value="2">Issue the command: <code>yum install BackupPC</code> and answer <code>y</code> to the question about installation. <ol type="a"> <li>Where did ''yum'' get the BackupPC software?</li> <li>Why could ''yum'' install BackupPC when rpm couldn't?</li> </ol> </li> <li>Issue an RPM query to verify that BackupPC is installed. Record this command in your lab log-book.</li> <li>Issue the command: <code>yum remove BackupPC</code></li> <li>Issue an RPM query to verify that BackupPC is no longer installed. Record this command in your lab log-book.</li> <li>Install <code>nled</code> using '''yum'''. Record this command in your lab log-book.</li> <li>Issue this command: <code>yum info cups</code></li></ol>::* Based on the result, do you think that cups is a useful package for your system? If not, try removing it.<ol> <li value="8">Unused and unneeded software can present a security risk and ties up disk space needlessly. Find at least 4 other packages that you're not using on your system, and remove them. Be careful to ensure that removing those packages does not also remove other software that you do need.</li></ol> '''Answer the Investigation 3 observations / questions in your lab log book.''' =Logical Volume Management (Introduction)= == Check Current LVM Information Prior to Performing Investigations == '''LVM''' ('''Logical Volume Management''') is used to manage hard disk drives / partitions for Unix/Linux systems. LVM provides more flexibility than just working with hard disks / hard disk partitions. '''Volume Groups''' are areas used to define '''Physical Volumes''' (i.e. hard disks, disk partitions, or other forms of storage devices). '''Logical Volumes''' are then used to relate directories (mount points) to a specific physical volume or for a "range" or "span" of physical volumes. Therefore, LVM allows more flexibility and growth potential for Linux systems (for example, having Logical volumes span multiple hard disks). Fedora uses LVM by default upon installation. Other Linux distributions may provide the capacity to install LVM, or later install and then use Logical Volume Management. '''Although the concept of LVM is simple, it takes practice and preparation (or "thinking ahead") in order to correctly use this valuable tool'''. It is important for students to gain an understanding of LVM, and how to manage their file-systems using LVM. It is recommended for students to read the following resource prior to this lab and/or return to the following resource while performing this lab: [[Logical Volume Management]] At this point, having completed [[OPS235 Lab 2|Lab 2]] you should have roughly the following disk storage setup:<br />('''Note:''' These results are output from the '''vgs''', '''lvs''', and '''pvs''' commands that provide volume group, physical volume and logical volume information for each of the virtual machines that you created in lab2. Before proceeding, check these values with your own system to see if you are generally "on the right track".<br /><br /> * '''fedora1'''  VG #PV #LV #SN Attr VSize VFree vg_fedora1 1 2 0 wz--n- 9.50g 0  PV VG Fmt Attr PSize PFree /dev/vda3 vg_fedora1 lvm2 a-- 9.50g 0  LV VG Attr LSize Origin Snap% Move Log Copy% Convert lv_root vg_fedora1 -wi-ao 8.03g lv_swap vg_fedora1 -wi-ao 1.47g  * '''fedora2'''  VG #PV #LV #SN Attr VSize VFree vg_fedora2 1 3 0 wz--n- 14.50g 3.25g  PV VG Fmt Attr PSize PFree /dev/vda3 vg_fedora2 lvm2 a-- 14.50g 3.25g  LV VG Attr LSize Origin Snap% Move Log Copy% Convert lv_home vg_fedora2 -wi-ao 1.97g lv_root vg_fedora2 -wi-ao 7.81g lv_swap vg_fedora2 -wi-ao 1.47g  * '''fedora3 (Note: This VM has no GUI installed)''' VG #PV #LV #SN Attr VSize VFree vg_fedora3 1 3 0 wz--n- 9.51g 0  PV VG Fmt Attr PSize PFree /dev/vda3 vg_fedora3 lvm2 a-- 9.51g 0  LV VG Attr LSize Origin Snap% Move Log Copy% Convert lv_home vg_fedora3 -wi-ao 1.00g lv_root vg_fedora3 -wi-ao 8.00g lv_swap vg_fedora3 -wi-ao 520.00m * '''f17host (i.e. "removable hard disk" or "disk pack")''' Does not use LVM. Confirm this using the same commands used above. {{Admon/note|VM Backups and Recovery|Most of these investigations will take place in your virtual machines. If you make a significant mistake, your virtual machine may not boot. Remember that you created backups of your virtual machines in Lab 2, and you can restore them if something goes wrong.<br /><br />'''Remember: if you did not create backups for all of your VMs, then you don't have any restoration points to fall-back to!'''|}} == Investigation 4: Extend the size of lv_root using command-line tools == Perform this investigation in fedora3. Let's say that you have run out of disk space on your computer (fedora3), you need more space on the root filesystem, perhaps to host more webpages or a larger database or new software. What are your options? Getting a replacement harddrive would probably require reinstallation of the operating system and backup/restore of the data. Because we're using LVM though - we can avoid that. We can add a new harddrive (which will serve as a physical volume) to the volume group, and extend the root logical volume to make use of the new available space. '''Perform the following operations to increase the size of lv_root in fedora3:''' <u>'''<font>Steps:</font>'''</u> <ol> <li>Run the following commands and make note of the output:</li> <code>ls /dev/vd* pvs vgs lvs df -h</code> <li>Open the fedora3 virtual machine console</li> <li>Go to the hardware details view</li> <li>Click "Add Hardware" and add a new storage device of 2GBs, make sure it's a VirtIO disk.</li> <li>Go back to the console view</li> <li>Run the same ls command now, what's changed?</li> <li>Now we'll make the new device as a physical volume, add it to the volume group, and extend lv_root:</li> <code>pvcreate /dev/vdb  vgextend vg_fedora3 /dev/vdb  lvextend -l +100%FREE -r vg_fedora3/lv_root</code> <li>Now rerun the ls/pvs/vgs/lvs/df commands. What has changed and what caused those changes?</li> <li>Among the changes, note that your root filesystem is now 2GB bigger - and you have not even rebooted your machine!</li></ol> '''Answer the Investigation 4 observations / questions in your lab log book.''' == Investigation 5: How are LVMs managed using system-config-lvm? == '''Perform this investigation on the VM named ''<u>fedora2</u>''.'''[[Image:Ops235_lab4_1.png|thumb|right|Screenshot of system-config-lvm in Fedora. Click to enlarge.]]# Let's learn to administer (manage) our LVM graphically for our '''Fedora2''' Virtual Machine.<br />Fedora provides a tool called <code>system-config-lvm</code> to graphically administer LVM. It will appear on the menu as '''Application'''>'''Other'''>'''Logical Volume Management'''. The package may not be installed by default, so you will need to install it by issuing: (<code>yum install system-config-lvm</code>).<ol> <li value="2">Use this tool to determine the current LVM configuration by clicking on the appropriate element and reading the properties in the right-hand panel -- write down the answers: <ol type="a"> <li>What are the names and sizes of the '''PV'''s?</li> <li>What is the name and size of the '''VG'''?</li> <li>What are the names and sizes of the '''LV'''s?</li> <li>Is there any space in the VG which is not allocated to a LV?</li> </ol> </li> <li>Increase the size of the home file-system to '''2 GB''': <ol type="a"> <li>Click on the LV containing the '''home''' filesystem.</li> <li>Click on ''Edit Properties''.</li> <li>Change the size to '''2 GB''' and click ''Ok''.</li> </ol> <li>Create a '''new 2G LV''' (LV Properties: linear) containing an ext4 filesystem named lv_archive and mount it at '''/archive''' <ol type="a"> <li>Click on ''Logical View''.</li> <li>Click the ''Create New Logical Volume''.</li> <li>Set the name, size, filesystem, and mount point.</li> <li>Click ''Ok''.</li> </ol> <li>Backup <code>'''/etc'''</code> into <code>'''/archive'''</code></li></ol>::* Copy the files in /etc into the filesystem mounted at <code>/archive</code><br />(use the graphical tools or the command line. If using cp, remember to use the -R option).<ol> <li value="6">Shrink the size of <code>lv_archive</code> to '''1 GB'''.</li> <li>Try shrinking the home file-system. What happens? Why?</li></ol> '''Answer the Investigation 5 observations / questions in your lab log book.''' = Updated backup instructions = If you completed this lab correctly - please make sure you are still making full backups of your virtual machines. Remember adding a new harddrive to fedora3? You will need to back up that drive as well. If you don't - you will only have half of your machine backed up, which is of no use for a recovery. = Completing the lab = {{Admon/important|Time for a new backup!|If you have successfully completed this lab, make a new backup of your virtual machines.}} '''Notes:'''# rpm command options# yum command options# How to use pvs/vgs/lvs/df/pvcreate/vgextend/lvextend# Answer to this question "What is the license of the nautilus package?" '''Arrange evidence for each of these items on your screen, then ask your instructor to review them and sign off on the lab's completion:'''# nled installed on the host (disk pack - main system f16host).# Unnecessary/unused packages have been deleted (list at least 4, and show that they are no longer installed).# Fresh backup of the virtual machines. = Preparing for the Quizzes == # What is a VG? PV? LV? # What commands are used to determine VG / PV / LV information?# What does yum do that rpm does not?# List the steps to install a package via rpm command.# List the steps to determine detailed information regarding an install package.# List the steps to remove a package via rpm command.# List the steps to install a package using the yum command.# List the steps to remove a package using the yum command.# What is the total size of the "main" VG on your system?# How do you create a LV?# How do you delete an LV?# How would you increase the size of the root filesystem by 50 MB?